For six years, Charlie Miller drove and repaired some of the biggest, toughest trucks out there: monster trucks. His road into the sport began in 1990 when he installed a lift on his pickup truck.

Miller turned his truck into an off-road vehicle, and he and his friends began to use it for racing. He said that when you take a truck off road and drive it as hard as they did, things tend to break.

"I didn't have the money to have somebody else fix it, so I learned as I went. I've been tinkering and messing with them for 23 years now," he said.

Eventually, he got into mud racing and tough-truck racing. He was on a tough-truck tour with a monster truck show when he said he would help out on some of the repairs on a truck.

"Eventually there was an opening for Paul Shafer Motorsports, and I took it. It was just kind of being at the right place at the right time," he said.

In 2005, Miller was crew chief for the Kid Rock monster truck, an award-winning truck. He's also driven monster trucks like Rampage and Bearfoot.

Many hours go in to fixing the vehicle each week between shows.

"One hundred hours a week. Literally almost 100 hours each week," he said. "A lot of that depends on how much damage was done the week before. When we were in the racing setting, we were under the gun to get it fixed."

He eventually got out of the monster truck business. He retired from full-time racing in 2007. He still misses it, but he said he still gets calls to fill in from time to time.

"Probably a show a year," he said.

Just because his full-time racing days are over, that doesn't mean he's done tinkering with trucks.

Recently Miller and his wife, Christy, moved back to Madison to open a mechanic and automotive customization shop, Monsterworks Automotive & Off Road.

Miller says the name implies they only do work on off-road vehicles and customization work. However, he says they'll fix anything from a lawn mowers to semi-trucks at the shop.

"We work on pretty much anything automotive," he said.

While Miller handles all the repairs, Christy works as operations manager and pays the bills.

"I do the paperwork because he hates it," she said.

The Millers said they had been thinking about opening a repair shop for three years before finally pulling the trigger. Christy Miller doesn't mind doing the paperwork, because the shop is keeping them both pretty happy.

"Seeing him in his element makes me very, very happy. He was miserable (at his previous job) and I hated seeing him like that."

Together, they say they're running a laid-back auto shop.

"We're not a pushy shop. Whereas a lot of people come in for an oil change and (other repair shops) come out and tell you need brakes, you need new wheel bearings, you need new tires, you need new wipers and you need a cabin air filter. If you just want an oil change, that's what you're going to get," Charlie Miller said.

Christy Miller said, business has been good. There have been mostly small jobs, like oil changes.

But just because Charlie Miller mostly does that kind of work now, it doesn't mean he's not helping to fix monster trucks.

"He still has guys in the monster truck industry that will call him and ask him a question about an engine because they're stumped," Christy Miller said.

He still has time to customize trucks too, which he says is his passion.

A few years ago, he got a red Dodge truck that wouldn't run. Over the years, he's overhauled the engine, added a lift kit and installed giant tires to his new project. All together, he estimates more than 60 hours spent working on the truck.

He says his plan is to install a step so his wife and children can access the truck a little easier.

Recently, he started taking his love of customization home with him in a different way.

His 20-month-old daughter loves coming to the shop and seeing her father work. So, he decided to foster that affection by customizing one of her toys.